However, “[t]hat a given combination would not be made by businessmen for economic reasons does not mean that persons skilled in the art would not make the combination because of some technological incompatability. Only the latter fact would be relevant.” In re Farrenkopf, 713 F.2d 714, 718 (Fed. Cir. 1983) (citing Orthopedic Equip. Co. v. United States, 702 F.2d 1005, 1013 (Fed. Cir. 1983)).